Medical fluids and drug products (e.g., drugs) can be administered to a patient through the use of drug delivery devices, such as autoinjectors or on-body injectors or infusers. These devices may replace delivery systems using the combination of a syringe and a vial of the medical fluid or drug product or a pre-filled syringe. Autoinjectors and on-body injectors may be used to automate the needle or cannula insertion and the drug delivery or administration process, thereby simplifying the process for certain patient groups or sub-groups for which use of the syringe/vial combination or pre-filled syringe systems would be disadvantageous, such as groups or sub-groups demonstrating physiological or psychological impediment.
In some instances, after automated insertion of the needle or cannula, the autoinjectors and on-body injectors may continue to allow drug to pass through the needle or cannula even though a component of the device (e.g., injector) has become detached from the patient and the needle or cannula no longer is inserted into the patient. This has several consequences. First, the patient does not receive the full dose of the drug, which may have a negative effect on the patient. Second, the patient may not be aware of the fact that the full dose of the drug has not been delivered, leaving the patient with the false impression that the entire dose has been delivered when it has not. Third, even if the patient is aware of the fact that the full dose has not been delivered, the patient may be unable to determine just how much of the dose was delivered. Conversely, the patient may not be able to determine how much of the dose was not delivered.
As set forth in more detail below, the present disclosure provides an improved drug delivery device embodying advantageous alternatives to the conventional devices and methods.